Vehicle users can forget to take personal items that they have temporarily stored in their vehicle when they later leave the vehicle. This can cause the user significant inconvenience and annoyance. Also, the forgotten item may have a significant value and may be visible, which could encourage a thief to attempt to break into the vehicle. Typical items often left behind include a mobile phone, wallet, laptop, house keys or sunglasses.
Known radio frequency identification (RFID) systems have been used to locate, track and/or identify items in a wide range of applications. Such systems are wireless and non-contact; they use radio frequency electromagnetic fields to transfer data from a tag attached to the item. The tag contains electronically stored information which may be read by a user using a reader device. The tag can be passive (it does not require a battery) and is powered and read at short ranges using an active reader. When used for locating or tracking, typically the user is informed by the reader when the item enters the range of the reader. However, RFID systems allow only one-way communication (from the tag at the item to the reader being operated by the user).
Near field communication (NFC) devices are a development of RFID technology but allow two-way communication. To date, they have been used mainly for payment systems (such as Google Wallet®)), smart cards, key fobs and the like. Many modern smartphones can operate as an active NFC device (for sending or receiving data).